Three people remain in custody over what police describe as the biggest money laundering operation ever in Northern Ireland.
More than €250 million was seized over a 48-hour period in recent days.
15 properties were searched, with the police operation focusing on the international dealings of Irish crime gangs.
They are alleged to have been using shell companies as a disguise since 2011.
Police say groups across Europe, the Middle East and Asia are involved.
Detective Chief Inspector Ian Wilson believes the gangs were involved in a range of illegal activities.
"We're probably talking more about drugs, prostitution, human trafficking, basically any acquisitive crime anytime you have a large amount of money that needs laundered," said Det. Chief Inspector Wilson.